The invention relates to a sensor in a vehicle door handle, particularly to but not exclusively limited to a sensor in a passenger vehicle door handle.
Keyless entry systems to vehicles generally comprise an RF receiver in the vehicle tuned to a particular frequency and an RF transmitter tuned to the same frequency. The owner of the vehicle locks and unlocks the vehicle and/or activates and deactivates the vehicle alarm or immobilizer system using the RF transmitter.
After the vehicle has been locked and the alarm activated by the user, the electronics of the vehicle are still active and it has been proposed to deactivate the electronics in some way so as to effect an electronic xe2x80x9cdeadlockingxe2x80x9d of the vehicle.
According to one aspect of the invention there is provided a sensor in a vehicle door handle. The handle comprises a fixed part and a movable part. The sensor comprising a magnet and a magnet-actuated switch whereby movement of the movable part relative to the fixed part causes the magnet to activate the switch.
In that way a system can be provided in which actuation of the vehicle door handle activates or deactivates the vehicle""s electronics.
Preferably, the sensor comprises a flux blocking means arranged between the magnet and the switch to prevent magnetic flux from the magnet actuating the switch. The blocking means may be arranged to expose the switch to magnetic flux when the movable part moves relative to the fixed part of the hand. The flux blocking means may comprise a vane of flux blocking material arranged between the magnet and the switch.
Preferably, two switches are provided, one arranged on each side of the magnet. In such a case, two flux blocking means may be provided, each flux blocking means being arranged between the magnet and a respective switch. Preferably, where two switches and two flux blocking means are provided, the sensor is arranged such that one switch is actuated by movement of the movable part relative to the fixed part in a first direction. The other switch is actuated by movement of the movable part relative to the fixed part in the opposite direction.
In another embodiment, the magnet is arranged on one of the fixed part and movable part and the magnet-actuated switch is arranged on the other of the fixed part and movable part. The sensor being arranged such that at a rest position of the movable part the magnet does not interact with the switch and movement of the movable part relative to the fixed part causes the magnet to actuate the switch. Preferably, two switches are provided. The sensor being arranged such that at the rest position of the movable part relative to the fixed part neither switch is actuated and so that movement of the movable part relative to the fixed part in one direction actuates one switch and movement of the movable part relative the fixed part in the opposite direction actuates the other switch. Preferably, the magnet is arranged on the movable part and each switch is arranged on the fixed part.
The magnet-actuated switch is preferably a reed switch. Alternatively, a Hall effect switch or a giant magneto resistive (GMR) can be used.
Preferably, the sensor can be retrofitted to an existing vehicle door handle.
According to another aspect of the invention, there is provided a vehicle door handle comprising a fixed part, a movable part and a sensor. The sensor comprising a magnet and a magnet-actuated switch whereby movement of the movable part relative to the fixed part causes the magnet to actuate the magnet-actuated switch.
According to a further aspect of the invention there is provided a sensor for a vehicle door handle comprising a magnet, a magnet-actuated switch and means for blocking magnetic flux arranged between the magnet and the magnet-actuated switch. The magnet and magnet-actuated switch are arranged on the movable part and fixed part and the flux blocking means is arranged on the other of the movable part and fixed part so that movement of the movable part relative to the fixed part moves the flux blocking means relative to the magnet and magnet-actuated switch so as to expose the magnet-actuated switch to magnet flux from the magnet, thereby actuating the magnetic actuated switch.